Content and Uptake of Nutrients with Plant Biomass of Potatoes Depending on Potassium Fertilization

The influence of potassium fertilizer source and the increasing potassium fertilization levels (0, 200, 400 and 600 mg K2O/kg soil) supplied either as K(2)SO4 or KCl at equal nitrogen and phosphorus fertilizer background (200 mg N/kg and 150 mg P2O5/kg soil) on the content and the uptake of nutrient elements from the soil in potato plant parts was studied. Pot experiment was carried out. The fertilization with K2SO4 decreased N content in roots from 2.91% at level K-200 to 2.52% at level K-600 and increased N content in aboveground biomass compared to the control and variants fertilized with KCl. The increasing KCl rates led to decreasing of N content in aboveground biomass from 4.03% at K-200 to 2.34% at potassium level K-400. Nitrogen content in tubers at variants fertilized with K decreased compared to the control. Potassium fertilization did not influence considerably P content in the plant parts. The K content in plant parts at variants fertilized with KCl was higher than the plants fertilized with K2SO4. Approximately 74% of absorbed nitrogen from the soil was allocated in the above ground biomass. The rest of the nitrogen was distributed between roots (17%) and tubers (9%). The highest P uptake was determined in control plants. The quantity of the uptaken K allocated in aboveground biomass was the highest (83%). The rest of K was distributed between roots (11%) and tubers (6%). (C) 2015 The Authors. Published by Elsevier B.V.